Scottish Thistle Plant?

I heard about the plant scottish thistle. Some people love it and it has become an important symbol, I saw the plant on rings and tatoos.
Since I'm working on my garden, I want more info on the scottish thistle and where I can buy it from.
Does anyone know how the Scottish Thistle came over to America?? I can't find that information anywhere.

The thistle is well-known as a symbol of Scotland, but it is of course found in other countries, and is found in Texas where I live.

As a young teenager I loved these plants that grew wild in my Dad's cow pasture. He hated the thistles, said they were bad for his cows.

The prickly purple thistle was adopted as the Emblem of Scotland during the rein of Alexander III (1249 -1286). Legend has it that an Army of King Haakon of Norway, intent on conquering the Scots landed at the Coast of Largs at night to surprise the sleeping Scottish Clansmen. In order to move more stealthily under the cover of darkness the Norsemen removed their footwear.

As they drew near to the Scots it wasn't the only thing hiding under the cover of darkness. For one of Haakon's men unfortunately stood on one of these spiny little defenders and shrieked out in pain, alerting the Clansmen of the advancing Norsemen. Needless to say the Scots who won the day.

A Scottish thistle has very prickly leaves. Purple and sometimes pink heads will blossom. They are very pretty with features that resemble a dandelion head. You can purchase seeds on the Internet. Don't bother looking in home gardening centers, they won't have them. If they do, then feel lucky that you live in an area that provides unique and unusual items.